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path: root/drivers/of/overlay.c
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2021-05-03of: overlay: Remove redundant assignment to retJiapeng Chong
Variable ret is set to zero but this value is never read as it is overwritten with a new value later on, hence it is a redundant assignment and can be removed. Cleans up the following clang-analyzer warning: drivers/of/overlay.c:1197:2: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]. drivers/of/overlay.c:1026:2: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/1619347258-55002-1-git-send-email-jiapeng.chong@linux.alibaba.com Signed-off-by: Rob Herring <robh@kernel.org>
2021-04-28Merge tag 'devicetree-for-5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull devicetree updates from Rob Herring: - Refactor powerpc and arm64 kexec DT handling to common code. This enables IMA on arm64. - Add kbuild support for applying DT overlays at build time. The first user are the DT unittests. - Fix kerneldoc formatting and W=1 warnings in drivers/of/ - Fix handling 64-bit flag on PCI resources - Bump dtschema version required to v2021.2.1 - Enable undocumented compatible checks for dtbs_check. This allows tracking of missing binding schemas. - DT docs improvements. Regroup the DT docs and add the example schema and DT kernel ABI docs to the doc build. - Convert Broadcom Bluetooth and video-mux bindings to schema - Add QCom sm8250 Venus video codec binding schema - Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile Technologies Inc. - Cleanup of DT schema type references on common properties and standard unit properties * tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (64 commits) powerpc: If kexec_build_elf_info() fails return immediately from elf64_load() powerpc: Free fdt on error in elf64_load() of: overlay: Fix kerneldoc warning in of_overlay_remove() of: linux/of.h: fix kernel-doc warnings of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses dt-bindings: bcm4329-fmac: add optional brcm,ccode-map docs: dt: update writing-schema.rst references dt-bindings: media: venus: Add sm8250 dt schema of: base: Fix spelling issue with function param 'prop' docs: dt: Add DT API documentation of: Add missing 'Return' section in kerneldoc comments of: Fix kerneldoc output formatting docs: dt: Group DT docs into relevant sub-sections docs: dt: Make 'Devicetree' wording more consistent docs: dt: writing-schema: Include the example schema in the doc build docs: dt: writing-schema: Remove spurious indentation dt-bindings: Fix reference in submitting-patches.rst to the DT ABI doc dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3 dt-bindings: media: video-interfaces: Drop the example devicetree: bindings: clock: Minor typo fix in the file armada3700-tbg-clock.txt ...
2021-04-21of: overlay: Fix kerneldoc warning in of_overlay_remove()Rob Herring
'*ovcs_id' causes a warning because '*' is treated as bold markup: Documentation/devicetree/kernel-api:56: ../drivers/of/overlay.c:1184: WARNING: Inline emphasis start-string without end-string. Fix this by using the normal '@' markup for function parameters. That appears to be enough to keep the '*' from being interpretted as markup. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Frank Rowand <frowand.list@gmail.com> Link: https://lore.kernel.org/r/20210421154548.1192903-1-robh@kernel.org/ Signed-off-by: Rob Herring <robh@kernel.org>
2021-04-08of: unittest: overlay: ensure proper alignment of copied FDTFrank Rowand
The Devicetree standard specifies an 8 byte alignment of the FDT. Code in libfdt expects this alignment for an FDT image in memory. kmemdup() returns 4 byte alignment on openrisc. Replace kmemdup() with kmalloc(), align pointer, memcpy() to get proper alignment. The 4 byte alignment exposed a related bug which triggered a crash on openrisc with: commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9") as reported in: https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/ Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Link: https://lore.kernel.org/r/20210408204508.2276230-1-frowand.list@gmail.com Signed-off-by: Rob Herring <robh@kernel.org>
2021-04-07of: properly check for error returned by fdt_get_name()Frank Rowand
fdt_get_name() returns error values via a parameter pointer instead of in function return. Fix check for this error value in populate_node() and callers of populate_node(). Chasing up the caller tree showed callers of various functions failing to initialize the value of pointer parameters that can return error values. Initialize those values to NULL. The bug was introduced by commit e6a6928c3ea1 ("of/fdt: Convert FDT functions to use libfdt") but this patch can not be backported directly to that commit because the relevant code has further been restructured by commit dfbd4c6eff35 ("drivers/of: Split unflatten_dt_node()") The bug became visible by triggering a crash on openrisc with: commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9") as reported in: https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/ Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20210405032845.1942533-1-frowand.list@gmail.com Signed-off-by: Rob Herring <robh@kernel.org>
2021-03-27of: Add missing 'Return' section in kerneldoc commentsRob Herring
Many of the DT kerneldoc comments are lacking a 'Return' section. Let's add the section in cases we have a description of return values. There's still some cases where the return values are not documented. Cc: Frank Rowand <frowand.list@gmail.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/20210325164713.1296407-8-robh@kernel.org
2021-03-24of: overlay: fix for_each_child.cocci warningskernel test robot
Function "for_each_child_of_node" should have of_node_put() before goto. Generated by: scripts/coccinelle/iterators/for_each_child.cocci Fixes: 82c2d81361ec ("coccinelle: iterators: Add for_each_child.cocci script") CC: Sumera Priyadarsini <sylphrenadin@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: kernel test robot <lkp@intel.com> Signed-off-by: Julia Lawall <julia.lawall@inria.fr> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Tested-by: Frank Rowand <frank.rowand@sony.com> Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2103221918450.2918@hadrien Signed-off-by: Rob Herring <robh@kernel.org>
2021-03-23of: overlay: Fix function name disparityLee Jones
Fixes the following W=1 kernel build warning(s): drivers/of/overlay.c:147: warning: expecting prototype for of_overlay_notifier_register(). Prototype was for of_overlay_notifier_unregister() instead Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: devicetree@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20210318104036.3175910-10-lee.jones@linaro.org
2020-04-17of: overlay: kmemleak in dup_and_fixup_symbol_prop()Frank Rowand
kmemleak reports several memory leaks from devicetree unittest. This is the fix for problem 4 of 5. target_path was not freed in the non-error path. Fixes: e0a58f3e08d4 ("of: overlay: remove a dependency on device node full_name") Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2020-01-08of: overlay: Remove blank line between assignment and checkGeert Uytterhoeven
There used to be blank lines between assignment and check of the __of_changeset_revert_entries() result, to make the phandle cache management operations stand out. After the removal of those operations in commit 90dc0d1ce890419f ("of: Rework and simplify phandle cache to use a fixed size"), there is no longer a reason to have such a blank line. Remove the blank line, to rejoin visibly the status assignement and check, and to match coding style. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rob Herring <robh@kernel.org>
2019-12-24of: Rework and simplify phandle cache to use a fixed sizeRob Herring
The phandle cache was added to speed up of_find_node_by_phandle() by avoiding walking the whole DT to find a matching phandle. The implementation has several shortcomings: - The cache is designed to work on a linear set of phandle values. This is true for dtc generated DTs, but not for other cases such as Power. - The cache isn't enabled until of_core_init() and a typical system may see hundreds of calls to of_find_node_by_phandle() before that point. - The cache is freed and re-allocated when the number of phandles changes. - It takes a raw spinlock around a memory allocation which breaks on RT. Change the implementation to a fixed size and use hash_32() as the cache index. This greatly simplifies the implementation. It avoids the need for any re-alloc of the cache and taking a reference on nodes in the cache. We only have a single source of removing cache entries which is of_detach_node(). Using hash_32() removes any assumption on phandle values improving the hit rate for non-linear phandle values. The effect on linear values using hash_32() is about a 10% collision. The chances of thrashing on colliding values seems to be low. To compare performance, I used a RK3399 board which is a pretty typical system. I found that just measuring boot time as done previously is noisy and may be impacted by other things. Also bringing up secondary cores causes some issues with measuring, so I booted with 'nr_cpus=1'. With no caching, calls to of_find_node_by_phandle() take about 20124 us for 1248 calls. There's an additional 288 calls before time keeping is up. Using the average time per hit/miss with the cache, we can calculate these calls to take 690 us (277 hit / 11 miss) with a 128 entry cache and 13319 us with no cache or an uninitialized cache. Comparing the 3 implementations the time spent in of_find_node_by_phandle() is: no cache: 20124 us (+ 13319 us) 128 entry cache: 5134 us (+ 690 us) current cache: 819 us (+ 13319 us) We could move the allocation of the cache earlier to improve the current cache, but that just further complicates the situation as it needs to be after slab is up, so we can't do it when unflattening (which uses memblock). Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Frank Rowand <frowand.list@gmail.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Frank Rowand <frowand.list@gmail.com> Tested-by: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Rob Herring <robh@kernel.org>
2019-11-26of: overlay: add_changeset_property() memory leakFrank Rowand
No changeset entries are created for #address-cells and #size-cells properties, but the duplicated properties are never freed. This results in a memory leak which is detected by kmemleak: unreferenced object 0x85887180 (size 64): backtrace: kmem_cache_alloc_trace+0x1fb/0x1fc __of_prop_dup+0x25/0x7c add_changeset_property+0x17f/0x370 build_changeset_next_level+0x29/0x20c of_overlay_fdt_apply+0x32b/0x6b4 ... Fixes: 6f75118800ac ("of: overlay: validate overlay properties #address-cells and #size-cells") Reported-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Tested-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Rob Herring <robh@kernel.org>
2019-01-10of: Remove struct device_node.type pointerRob Herring
Now that all users of device_node.type pointer have been removed in favor of accessor functions, we can remove it. Cc: Frank Rowand <frowand.list@gmail.com> Cc: devicetree@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-11-08of: overlay: set node fields from properties when add new overlay nodeFrank Rowand
Overlay nodes added by add_changeset_node() do not have the node fields name, phandle, and type set. The node passed to __of_attach_node() when the add node changeset entry is processed does not contain any properties. The node's properties are located in add property changeset entries that will be processed after the add node changeset is applied. Set the node's fields in the node contained in the add node changeset entry and do not set them to incorrect values in add_changeset_node(). A visible symptom that is fixed by this patch is the names of nodes added by overlays that have an entry in /sys/bus/platform/drivers/*/ will contain the unit-address but the node-name will be <NULL>, for example, "fc4ab000.<NULL>". After applying the patch the name, in this example, for node restart@fc4ab000 is "fc4ab000.restart". Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: check prevents multiple fragments touching same propertyFrank Rowand
Add test case of two fragments updating the same property. After adding the test case, the system hangs at end of boot, after after slub stack dumps from kfree() in crypto modprobe code. Multiple overlay fragments adding, modifying, or deleting the same property is not supported. Add check to detect the attempt and fail the overlay apply. Before this patch, the first fragment error would terminate processing. Allow fragment checking to proceed and report all of the fragment errors before terminating the overlay apply. This is not a hot path, thus not a performance issue (the error is not transient and requires fixing the overlay before attempting to apply it again). After applying this patch, the devicetree unittest messages will include: OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/rpm_avail ... ### dt-test ### end of unittest - 212 passed, 0 failed The check to detect two fragments updating the same property is folded into the patch that created the test case to maintain bisectability. Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: check prevents multiple fragments add or delete same nodeFrank Rowand
Multiple overlay fragments adding or deleting the same node is not supported. Replace code comment of such, with check to detect the attempt and fail the overlay apply. Devicetree unittest where multiple fragments added the same node was added in the previous patch in the series. After applying this patch the unittest messages will no longer include: Duplicate name in motor-1, renamed to "controller#1" OF: overlay: of_overlay_apply() err=0 ### dt-test ### of_overlay_fdt_apply() expected -22, ret=0, overlay_bad_add_dup_node ### dt-test ### FAIL of_unittest_overlay_high_level():2419 Adding overlay 'overlay_bad_add_dup_node' failed ... ### dt-test ### end of unittest - 210 passed, 1 failed but will instead include: OF: overlay: ERROR: multiple overlay fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller ... ### dt-test ### end of unittest - 211 passed, 0 failed Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: make all pr_debug() and pr_err() messages uniqueFrank Rowand
Make overlay.c debug and error messages unique so that they can be unambiguously found by grep. Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: validate overlay properties #address-cells and #size-cellsFrank Rowand
If overlay properties #address-cells or #size-cells are already in the live devicetree for any given node, then the values in the overlay must match the values in the live tree. If the properties are already in the live tree then there is no need to create a changeset entry to add them since they must have the same value. This reduces the memory used by the changeset and eliminates a possible memory leak. Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: reorder fields in struct fragmentFrank Rowand
Order the fields of struct fragment in the same order as struct of_overlay_notify_data. The order in struct fragment is not significant. If both structs are ordered the same then when examining the data in a debugger or dump the human involved does not have to remember which context they are examining. Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: do not duplicate properties from overlay for new nodesFrank Rowand
When allocating a new node, add_changeset_node() was duplicating the properties from the respective node in the overlay instead of allocating a node with no properties. When this patch is applied the errors reported by the devictree unittest from patch "of: overlay: add tests to validate kfrees from overlay removal" will no longer occur. These error messages are of the form: "OF: ERROR: ..." and the unittest results will change from: ### dt-test ### end of unittest - 203 passed, 7 failed to ### dt-test ### end of unittest - 210 passed, 0 failed Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: use prop add changeset entry for property in new nodesFrank Rowand
The changeset entry 'update property' was used for new properties in an overlay instead of 'add property'. The decision of whether to use 'update property' was based on whether the property already exists in the subtree where the node is being spliced into. At the top level of creating a changeset describing the overlay, the target node is in the live devicetree, so checking whether the property exists in the target node returns the correct result. As soon as the changeset creation algorithm recurses into a new node, the target is no longer in the live devicetree, but is instead in the detached overlay tree, thus all properties are incorrectly found to already exist in the target. This fix will expose another devicetree bug that will be fixed in the following patch in the series. When this patch is applied the errors reported by the devictree unittest will change, and the unittest results will change from: ### dt-test ### end of unittest - 210 passed, 0 failed to ### dt-test ### end of unittest - 203 passed, 7 failed Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: add missing of_node_put() after add new node to changesetFrank Rowand
The refcount of a newly added overlay node decrements to one (instead of zero) when the overlay changeset is destroyed. This change will cause the final decrement be to zero. After applying this patch, new validation warnings will be reported from the devicetree unittest during boot due to a pre-existing devicetree bug. The warnings will be similar to: OF: ERROR: memory leak before free overlay changeset, /testcase-data/overlay-node/test-bus/test-unittest4 This pre-existing devicetree bug will also trigger a WARN_ONCE() from refcount_sub_and_test_checked() when an overlay changeset is destroyed without having first been applied. This scenario occurs when an error in the overlay is detected during the overlay changeset creation: WARNING: CPU: 0 PID: 1 at lib/refcount.c:187 refcount_sub_and_test_checked+0xa8/0xbc refcount_t: underflow; use-after-free. (unwind_backtrace) from (show_stack+0x10/0x14) (show_stack) from (dump_stack+0x6c/0x8c) (dump_stack) from (__warn+0xdc/0x104) (__warn) from (warn_slowpath_fmt+0x44/0x6c) (warn_slowpath_fmt) from (refcount_sub_and_test_checked+0xa8/0xbc) (refcount_sub_and_test_checked) from (kobject_put+0x24/0x208) (kobject_put) from (of_changeset_destroy+0x2c/0xb4) (of_changeset_destroy) from (free_overlay_changeset+0x1c/0x9c) (free_overlay_changeset) from (of_overlay_remove+0x284/0x2cc) (of_overlay_remove) from (of_unittest_apply_revert_overlay_check.constprop.4+0xf8/0x1e8) (of_unittest_apply_revert_overlay_check.constprop.4) from (of_unittest_overlay+0x960/0xed8) (of_unittest_overlay) from (of_unittest+0x1cc4/0x2138) (of_unittest) from (do_one_initcall+0x4c/0x28c) (do_one_initcall) from (kernel_init_freeable+0x29c/0x378) (kernel_init_freeable) from (kernel_init+0x8/0x110) (kernel_init) from (ret_from_fork+0x14/0x2c) Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08of: overlay: add tests to validate kfrees from overlay removalFrank Rowand
Add checks: - attempted kfree due to refcount reaching zero before overlay is removed - properties linked to an overlay node when the node is removed - node refcount > one during node removal in a changeset destroy, if the node was created by the changeset After applying this patch, several validation warnings will be reported from the devicetree unittest during boot due to pre-existing devicetree bugs. The warnings will be similar to: OF: ERROR: of_node_release(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11 OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/ hvac-medium-2 Tested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-09-07of: Convert to using %pOFn instead of device_node.nameRob Herring
In preparation to remove the node name pointer from struct device_node, convert printf users to use the %pOFn format specifier. Reviewed-by: Frank Rowand <frank.rowand@sony.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: netdev@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-07-16of: overlay: update phandle cache on overlay apply and removeFrank Rowand
A comment in the review of the patch adding the phandle cache said that the cache would have to be updated when modules are applied and removed. This patch implements the cache updates. Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") Reported-by: Alan Tull <atull@kernel.org> Suggested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-04-26of: overlay: Stop leaking resources on overlay removalJan Kiszka
Only the overlay notifier callbacks have a chance to potentially get hold of references to those two resources, but they are not supposed to store them beyond OF_OVERLAY_POST_REMOVE. Document the overlay notifier API, its constraint regarding pointer lifetime, and then remove intentional leaks of ovcs->overlay_tree and ovcs->fdt from free_overlay_changeset. See also https://lkml.org/lkml/2018/4/23/1063 and following. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-03-17of: overlay: Fix forgotten reference to of_overlay_apply()Geert Uytterhoeven
While technically the ovcs_id is still returned by of_overlay_apply(), this is an internal function. All public callers of of_overlay_remove() pass an ovcs_id returned by the public function of_overlay_fdt_apply(). Fixes: 39a751a4cb7e4798 ("of: change overlay apply input data from unflattened to FDT") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rob Herring <robh@kernel.org>
2018-03-05of: overlay: do not include path in full_name of added nodesFrank Rowand
Struct device_node full_name no longer includes the full path name when the devicetree is created from a flattened device tree (FDT). The overlay node creation code was not modified to reflect this change. Fix the node full_name generated by overlay code to contain only the basename. Unittests call an overlay internal function to create new nodes. Fix up these calls to provide basename only instead of the full path. Fixes: a7e4cfb0a7ca ("of/fdt: only store the device node basename in full_name") Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-03-04of: improve reporting invalid overlay target pathFrank Rowand
Errors while developing the patch to create of_overlay_fdt_apply() exposed inadequate error messages to debug problems when overlay devicetree fragment nodes contain an invalid target path. Improve the messages in find_target_node() to remedy this. Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-03-04of: change overlay apply input data from unflattened to FDTFrank Rowand
Move duplicating and unflattening of an overlay flattened devicetree (FDT) into the overlay application code. To accomplish this, of_overlay_apply() is replaced by of_overlay_fdt_apply(). The copy of the FDT (aka "duplicate FDT") now belongs to devicetree code, which is thus responsible for freeing the duplicate FDT. The caller of of_overlay_fdt_apply() remains responsible for freeing the original FDT. The unflattened devicetree now belongs to devicetree code, which is thus responsible for freeing the unflattened devicetree. These ownership changes prevent early freeing of the duplicated FDT or the unflattened devicetree, which could result in use after free errors. of_overlay_fdt_apply() is a private function for the anticipated overlay loader. Update unittest.c to use of_overlay_fdt_apply() instead of of_overlay_apply(). Move overlay fragments from artificial locations in drivers/of/unittest-data/tests-overlay.dtsi into one devicetree source file per overlay. This led to changes in drivers/of/unitest-data/Makefile and drivers/of/unitest.c. - Add overlay directives to the overlay devicetree source files so that dtc will compile them as true overlays into one FDT data chunk per overlay. - Set CFLAGS for drivers/of/unittest-data/testcases.dts so that symbols will be generated for overlay resolution of overlays that are no longer artificially contained in testcases.dts - Unflatten and apply each unittest overlay FDT using of_overlay_fdt_apply(). - Enable the of_resolve_phandles() check for whether the unflattened overlay is detached. This check was previously disabled because the overlays from tests-overlay.dtsi were not unflattened into detached trees. - Other changes to unittest.c infrastructure to manage multiple test FDTs built into the kernel image (access by name instead of arbitrary number). - of_unittest_overlay_high_level(): previously unused code to add properties from the overlay_base devicetree to the live tree was triggered by the restructuring of tests-overlay.dtsi and thus testcases.dts. This exposed two bugs: (1) the need to dup a property before adding it, and (2) property 'name' is auto-generated in the unflatten code and thus will be a duplicate in the __symbols__ node - do not treat this duplicate as an error. Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-01-08of: Use SPDX license tag for DT filesRob Herring
Convert remaining DT files to use SPDX-License-Identifier tags. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-08of: overlay: Make node skipping in init_overlay_changeset() clearerGeert Uytterhoeven
Make it more clear that nodes without "__overlay__" subnodes are skipped, by reverting the logic and using continue. This also reduces indentation level. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-08of: overlay: Fix out-of-bounds write in init_overlay_changeset()Geert Uytterhoeven
If an overlay has no "__symbols__" node, but it has nodes without "__overlay__" subnodes at the end (e.g. a "__fixups__" node), after filling in all fragments for nodes with "__overlay__" subnodes, "fragment = &fragments[cnt]" will point beyond the end of the allocated array. Hence writing to "fragment->overlay" will overwrite unallocated memory, which may lead to a crash later. Fix this by deferring both the assignment to "fragment" and the offending write afterwards until we know for sure the node has an "__overlay__" subnode, and thus a valid entry in "fragments[]". Fixes: 61b4de4e0b384f4a ("of: overlay: minor restructuring") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-06of: overlay: Fix (un)locking in of_overlay_apply()Geert Uytterhoeven
The special overlay mutex is taken first, hence it should be released last in the error path. of_resolve_phandles() must be called with of_mutex held. Without it, a node and new phandle could be added via of_attach_node(), making the max phandle wrong. free_overlay_changeset() must be called with of_mutex held, if any non-trivial cleanup is to be done. Hence move "mutex_lock(&of_mutex)" up, as suggested by Frank, and merge the two tail statements of the success and error paths, now they became identical. Note that while the two mutexes are adjacent, we still need both: __of_changeset_apply_notify(), which is called by __of_changeset_apply() unlocks of_mutex, then does notifications then locks of_mutex. So the mutex get released in the middle of of_overlay_apply() Fixes: f948d6d8b792bb90 ("of: overlay: avoid race condition between applying multiple overlays") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-06of: overlay: Fix memory leak in of_overlay_apply() error pathGeert Uytterhoeven
If of_resolve_phandles() fails, free_overlay_changeset() is called in the error path. However, that function returns early if the list hasn't been initialized yet, before freeing the object. Explicitly calling kfree() instead would solve that issue. However, that complicates matter, by having to consider which of two different methods to use to dispose of the same object. Hence make free_overlay_changeset() consider initialization state of the different parts of the object, making it always safe to call (once!) to dispose of a (partially) initialized overlay_changeset: - Only destroy the changeset if the list was initialized, - Make init_overlay_changeset() store the ID in ovcs->id on success, to avoid calling idr_remove() with an error value or an already released ID. Reported-by: Colin King <colin.king@canonical.com> Fixes: f948d6d8b792bb90 ("of: overlay: avoid race condition between applying multiple overlays") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-06of: overlay: Remove else after gotoGeert Uytterhoeven
If an "if" branch is terminated by a "goto", there's no need to have an "else" statement and an indented block of code. Remove the "else" statement to simplify the code flow for the casual reviewer. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-06of: Spelling s/changset/changeset/Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-19of: overlay: make pr_err() string uniqueFrank Rowand
The same error string occurs in drivers/of/resolver.c. Change the error here to more precisely describe this case, and avoid the possible confusion of looking in the wrong source location to understand the cause of an error. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-19of: overlay: pr_err from return NOTIFY_OK to overlay apply/removeFrank Rowand
A device tree overlay notifier can return NOTIFY_OK, NOTIFY_STOP, or an embedded errno. overlay_notify() incorrectly reports an error for NOTIFY_OK. Reported-by: atull@kernel.org Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: remove unneeded check for NULL kbasename()Frank Rowand
kbasename() will not return NULL if passed a valid string. If the parameter passed to kbasename() in this case is already NULL then the devicetree has been corrupted. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: remove a dependency on device node full_nameFrank Rowand
The "%pOF" printf format was recently added to print the full name of a device tree node, with the intent of changing the node full_name field to contain only the node name instead of the full path of the node. dup_and_fixup_symbol_prop() duplicates a property from the "/__symbols__" node of an overlay device tree. The value of each duplicated property must be fixed up to include the full path of a node in the live device tree. The current code uses the node's full_name for that purpose. Update the code to use the "%pOF" printf format to determine the node's full path. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: simplify applying symbols from an overlayFrank Rowand
The code to apply symbols from an overlay to the live device tree was implemented with the intent to be minimally intrusive on the existing code. After recent restructuring of the overlay apply code, it is easier to disintangle the code that applies the symbols, and to make the overlay changeset creation code more straight forward and understandable. Remove the extra complexity, and make the code more obvious. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: avoid race condition between applying multiple overlaysFrank Rowand
The process of applying an overlay consists of: - unflatten an overlay FDT (flattened device tree) into an EDT (expanded device tree) - fixup the phandle values in the overlay EDT to fit in a range above the phandle values in the live device tree - create the overlay changeset to reflect the contents of the overlay EDT - apply the overlay changeset, to modify the live device tree, potentially changing the maximum phandle value in the live device tree There is currently no protection against two overlay applies concurrently determining what range of phandle values are in use in the live device tree, and subsequently changing that range. Add a mutex to prevent multiple overlay applies from occurring simultaneously. Move of_resolve_phandles() into of_overlay_apply() so that it does not have to be duplicated by each caller of of_overlay_apply(). The test in of_resolve_phandles() that the overlay tree is detached is temporarily disabled so that old style overlay unittests do not fail. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: loosen overly strict phandle clash checkFrank Rowand
When an overlay contains a node that already exists in the live device tree, the overlay node is not allowed to change the phandle of the existing node. The existing check refused to allow an overlay node to set the node phandle even when the existing node did not have a phandle. Relax the check to allow an overlay node to set the phandle value if the existing node does not have a phandle. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: expand check of whether overlay changeset can be removedFrank Rowand
The test of whether it is safe to remove an overlay changeset looked at whether any node in the overlay changeset was in a subtree rooted at any more recently applied overlay changeset node. The test failed to determine whether any node in the overlay changeset was the root of a subtree that contained a more recently applied overlay changeset node. Add this additional check to the test. The test is still lacking any check for any phandle dependencies. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: detect cases where device tree may become corruptFrank Rowand
When an attempt to apply an overlay changeset fails, an effort is made to revert any partial application of the changeset. When an attempt to remove an overlay changeset fails, an effort is made to re-apply any partial reversion of the changeset. The existing code does not check for failure to recover a failed overlay changeset application or overlay changeset revert. Add the missing checks and flag the devicetree as corrupt if the state of the devicetree can not be determined. Improve and expand the returned errors to more fully reflect the result of the effort to undo the partial effects of a failed attempt to apply or remove an overlay changeset. If the device tree might be corrupt, do not allow further attempts to apply or remove an overlay changeset. When creating an overlay changeset from an overlay device tree, add some additional warnings if the state of the overlay device tree is not as expected. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: minor restructuringFrank Rowand
Continue improving the readability of overlay.c. The previous patches renamed identifiers. This patch is split out from the previous patches to make the previous patches easier to review. Changes are: - minor code restructuring - some initialization of an overlay changeset occurred outside of init_overlay_changeset(), move that into init_overlay_changeset() - consolidate freeing an overlay changeset into free_overlay_changeset() This patch is intended to not introduce any functional change. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: rename identifiers in dup_and_fixup_symbol_prop()Frank Rowand
More renaming of identifiers to better reflect what they do. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay: rename identifiers to more reflect what they doFrank Rowand
This patch is aimed primarily at drivers/of/overlay.c, but those changes also have a small impact in a few other files. overlay.c is difficult to read and maintain. Improve readability: - Rename functions, types and variables to better reflect what they do and to be consistent with names in other places, such as the device tree overlay FDT (flattened device tree), and make the algorithms more clear - Use the same names consistently throughout the file - Update comments for name changes - Fix incorrect comments This patch is intended to not introduce any functional change. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-17of: overlay.c: Convert comparisons to zero or NULL to logical expressionsFrank Rowand
Use normal shorthand for comparing a variable to zero. For variable "XXX": convert (XXX == 0) to (!XXX) convert (XXX != 0) to (XXX) Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>